Does GPL work on
Windows XP?

Yes, GPL does work on XP. I have it running quite well on a
1.4 GHz Celeron running XP Pro. It also works on XP Home.

However, there are some issues with GPL on XP that you may
need to work around, and there are some patches you'll probably
need to install.

GPL Upgrade Patches

Make sure you get the GPL 1.2 patch. GPL 1.2 enables Force
Feedback and makes many other improvements, especially in online
muliplayer racing. GPL 1.2 is essential for racing GPL on VROC.

If you're going to race online, also get the Disconnect Fix.
The Disconnect Fix greatly reduces the likelihood of being disconnected
from online races.

Both of these patches are available from www.papy.com. While you're there, get the
CPU Speed Fix too, because you may need
it now or in the future. Also (unless you have a Voodoo or Rendition
video card; the latter is highly unlikely!) get either the Direct3D
or OpenGL patch, or both.

Patch Installation
Note: Make sure you install the GPL 1.2 patch before you
install other patches! If you install the CPU
Speed Fix before you install the GPL 1.2 patch, GPL will
crash to the desktop when you try to go to the Mulitplayer screen.

Fortunately the fix is easy: copy the original gpl.exe from
the GPL CD to the GPL folder on your hard drive, reinstall the
GPL 1.2 patch, and then reinstall the Speed Patch.

Configuration Issues

There are a few things you may also need to do, depending
on your configuration:

File System. If GPL is on
an NTFS partition, you may find that GPL crashes to the desktop
when you try to launch it. The fix is simple: turn on fast indexing
for the GPL folder, and turn on the Fast Indexing service in
Windows XP. If you put GPL on a FAT32 partition, this won't be
an issue. (See Turning On
Fast Indexing and Installing
GPL on a FAT32 Partition, below.)

Video Card. If you are using
anything other than the now obsolete 3Dfx or Rendition video
cards, you'll need either the OpenGL or Direct3D rasterizer for
GPL, available from www.papy.com.
These should allow you to use hardware acceleration on most current
video cards, such as just about any GeForce and most Raedeon
video cards. TNT and older ATI cards are iffy, however. The alternative
is to use Software mode, which doesn't look nearly as good and
is slower.

You should also probably download the latest drivers for your
card from nVidia or ATI. I've had good luck with the most recent
WHQL-approved drivers (version 40.72) for my GeForce 2 Ultra.

CPU Speed. If your CPU is
faster than 1.4 GHz, you may find that GPL crashes to the desktop
when you launch it. If so, you probably need the CPU Speed Fix,
also available from www.papy.com.
Note that this patch also includes the Disconnect Fix, so you
don't need to apply the Disconnect Fix if you use the Speed Fix.
(See the Patch Installation
Note, above, for important information on GPL patch installation
sequence!)

Sound Card. If you are using
a SoundBlaster Live or Audigy sound card, you may have problems
with static in the sound, or worse. I've had static, popping
sounds, sound fading away, and various other annoying artifacts.
Some on-board sound cards also have problems, including causing
a crash to desktop when you get into the car in GPL.

One workaround that may help is to set the sound card's "Hardware
acceleration" slider one notch from the left. I also found
that setting the "Sample rate conversion quality" slider
to the far left improved my frame rate. (See Adjusting Sound Properties, below)

You can also experiment with new drivers, but after a lot of
frustration I found the best solution for me was to switch to
a different sound card. There seems to be a large variation in
results from one machine to another, and there's no guarantee
how any given machine will react to a given sound card or driver.

However, it's likely that you will get better results with a
new sound card. Many people have reported good results with SoundBlaster
Audigy 2 and Turtle Beach cards. I'm using an old Diamond Monster
MX 400 with good results.

Controllers. I have tried
Logitech Formula Force ("Old Red") and the newer Logitech
MOMO FF wheel (the newer model with stick shift). Both work fine,
but I prefer the Old Red; I dislike the extremely high gearing
of the MOMO because of the "flywheel effect" that it
introduces. This damps much of the feel and ruins FF for me.

I use CH Pro Pedals; they give me the most precise control over
braking and throttle.

USB Adapter. Note that the PDPI
L4 will not work on XP because XP does not recognize ISA cards.
If you already have a controller that needs a game port, you
might try the Radio Shack USB Adapter, catalog number 26-164.

I'm using this adapter with my (non-USB) CH Pro Pedals. I've
plugged a joystick into the pedals to supply the other two axes,
but I don't use the joystick except for calibration. I've got
the adapter's switch set on the Joystick A setting, and I calibrated
all four axes in Control Panel\Game Controllers before calibrating
in GPL and selecting the pedals for throttle and brake.

This setup seems to work fine, and seems to perform better than
using the game port on the sound card. However, occasionally
Windows seems to lose track of the wheel and pedals and I have
to revisit Game Controllers. Just going into Game Controllers
seems to reawaken Windows to their presence. Also if a dirty
pot causes spikes, it may be necessary to recaliibrate in Game
Controllers.

If you still have problems, try posting a message on the rec.autos.simulators
newsgroup or on the forum at www.racesimcentral.com. These are both excellent
sources of information, with quite a few people who are running
GPL and XP on various hardware configurations.

XP Tweaking Guide

If you're new to XP, you may not have performed certain tasks
like turning on Fast Indexing or adjusting sound properties before.
Here are some tips on how to perform certain tasks in XP. These
apply to XP Pro, but XP Home should be similar.

Turning on Fast Indexing

You need to take two steps: 1) turn on Fast Indexing for the
GPL folder, and 2) enable the Fast Indexing Service.

Turning on Fast Indexing for the GPL folder. To turn
on Fast Indexing for the GPL folder, open Windows Explorer, navigate
to the place where you installed GPL (by default, C:\SIERRA\gpl)
and right-click on the GPL folder. You'll get a popup called
GPL Properties. Near the bottom of the General sheet will be
an Advanced tab. Click this.

You'll get a new popup called Advanced Attributes. Check the
box labeled "For fast searching, allow Indexing Service
to index this folder". Click OK on both popups.

Turning on the Fast Indexing Service. To turn on the
Fast Indexing Service, open the Control Panel and open Administrative
Tools. Choose Services.

In the list of services you will find Indexing Service. Open
this and set the Startup Type to Automatic. Click the Start button,
and then click OK. The Indexing Service should now show in the
list as Started and Automatic.

Installing GPL on a
FAT32 Partition

If GPL still CTD's after you've turned on Fast
Indexing (and installed the CPU Speed
Fix if applicable) as suggested above, you can get around
the NTFS issue by moving GPL to a FAT32 drive or partition. (For
more information on how to create a FAT32 partition on XP, please
see Uwe Wulf's notes on FAT32 Partitions
on XP and your Windows XP documentation.)

Be sure you allow plenty of space on the FAT32 drive or partition.
The initial install of GPL takes only about 70 mb, but additional
tracks, high resolution car and track graphical enhancements,
and replay files (which can be very large) add up quickly. I recommend
at least 500 MB, and more - over 1 GB if you can afford it - is
good insurance.

Just for reference, my current GPL install takes nearly 2 GB,
including 1.4 GB of tracks (almost 150 of them). This isn't counting
replays. Saving a typical Intermediate Long race produces a replay
file which can easily exceed 40 mb. If you save a lot of races,
it doesn't take long to pile up hundreds of megabytes' worth of
replays.

Once you've created the FAT32 partition, reinstall GPL on it
and then reinstall the patches as listed above.

Adjusting Sound Properties

To get to the Hardware acceleration and Sample rate conversion
quality sliders sliders, open the Control Panel, choose Sounds
and Audio Devices, and click on the Advanced button in the Speaker
Settings area.

You'll get another popup called Advanced Audio Properties.
The Hardware acceleration and Sample rate conversion quality sliders
will be on the Performance sheet of this popup.

Troubleshooting Guide

Here's a list of common problems with GPL on XP, and what to
do about them.